Table 2 Association between investigated factors and opioid side effects reported in 9 studies included in the systematic review
Factors | Association [reference] | ||
|---|---|---|---|
None | Direct | Inverse | |
Sociodemographic | |||
Age (advanced) | Anorexia, itch, nausea [61]; constipation [40, 67]; confusion, drowsiness [40] | Constipation, dry mouth, hallucination [61] | Myoclonus and urinary hesitancy [61]; dry mouth, nausea [40] |
Gender (female) | Constipation [67]; itch, myoclonus, nausea, urinary hesitancy [61] | Anorexia, dry mouth [61] | |
Clinical | |||
Biochemical factors | Constipation [67] | ||
Glomerular Filtration Rate (GFR; low vs normal) | Fatigue, nausea and vomiting, pain, cognitive dysfunction [84] | Loss of appetite, constipation [84] | |
Cancer diagnosis | Constipation [67] | ||
Comorbidity (Charlson score) | Constipation [74] | ||
Terminal stage (decreasing weeks before death) | Nausea, vomiting [40] | Confusion, dry mouth, drowsiness, constipation [40] | |
Pain related | |||
Neuropathic pain (vs absence) | Dry mouth, confusion [40] | ||
Visceral pain (vs somatic pain) | Nausea, vomiting, constipation, dry mouth [40] | Confusion [40] | |
Drug use | |||
Co-use of ≥2 opioids | Constipation [74] | ||
Dose (high) | ADR [38]; constipation [67, 77, 78]; nausea [61, 77, 78]; dizziness, myoclonus [61]; dry mouth, emesis [78]; anorexia, somnolence, vomiting [77] | Urinary hesitancy [61] | Dry mouth [77] |
Length of therapy (days) | Constipation [67] | Constipation [74] | |
Switching | |||